1. Field of the Invention
The present invention relates to a transmission mechanism for an electrical nail gun, and more particularly to a transmission mechanism in which a solenoid is received in a cylinder of a flywheel, a clutch is located between the cylinder and an end side of a driving wheel, a magnetic field is produced by activating the solenoid to control engagement or disengagement of the driving wheel to transmit kinetic energy of the rotary flywheel.
2. Description of Related Art
An electrical nail gun is a type of tool used to drive nails into wood or some other kind of material. Usually, there is a battery pack or an AC electrical power source in a housing of the electrical nail gun to provide electrical power to a motor, thereby rotating the motor. A rotary kinetic energy of the motor is transformed into a linear kinetic energy by a transmission mechanism to drive a strike bar to impact nails.
Among a more advanced technology, many US patents, such as U.S. Pat. No. 6,607,111 and U.S. Pat. No. 6,669,072 and so on, teach a flywheel driven by a DC motor, a clutch assembly being capable of linear movement by traction of a wire disposed on an axis of a solenoid. The clutch assembly has a wire drum and connects to a driving stand via at least a wire. When a nail gun is driven by a user, the clutch assembly is moved along an axis direction to mesh with a flywheel which is rotating, thereby rotating the clutch assembly. Therefore, a rotary kinetic energy is transformed into a linear kinetic energy of the strike bar to then impact nails via traction of the wire. However, the structure of the clutch assembly is complicated due to too many components. The solenoid is disposed in the housing away from the flywheel, therefore, it is a disadvantage to save configuration room.
In addition, a number of patents, such as U.S.P 20050218177, WO No. 2005097428, and EP No. 1582300 and so on, teach a driver produced by a solenoid. The driver linearly pushes a swing arm forming a roller to swing. A driving stand of a stroke bar is pushed by the roller to urge the driving stand to mesh with a rotating flywheel. Thus, a rotary kinetic energy of the flywheel is transformed into a linear kinetic energy of a stroke bar to impact a nail. Wherein, the roller, the driving stand, and the flywheel cooperatively form a clutch assembly being capable of engagement or disengagement. However, during a long-term use, an abrasion may be produced by friction between the roller, the driving stand, and the flywheel to thereby broaden mesh clearance. When the driving stand of the stroke bar is pushed by the roller towards the flywheel to mesh with the flywheel, a component acting force is produced not along a direction of impacting the nail due to clearance, thereby affecting safety and stability as the driving stand is driving the stroke bar to impact the nail. Furthermore, the solenoid is disposed in the housing away from the flywheel or the clutch assembly; therefore, it is a disadvantage to save configuration room. Accordingly, the above-mentioned problems need to be further improved.